446 STEPHENSON'S PATENT 



their forks, and force them into the notches in the bottom of the forks. The re- 

 versing eccentrics, F' F", are thus brought into gear, and made to work the slides, 

 causing the motion of the pistons to be reversed by the steam being admitted on the 

 opposite side of them, and making the engine run in the opposite direction to its 

 former course ; the middle eccentric rods, e e", are at the same time lowered, as the 

 outside ones were before, allowing the forks upon them to clear the pins of the levers 

 ft" h'". The engine can then be propelled forward again by putting the hand lever 

 over into its front position ; dropping the rods of the outer reversing eccentrics out of 

 gear, and drawing up the inner rods of the forward working eccentrics to force the 

 levers of the weigh-bars into the opposite positions by their forks, and take hold of 

 the pins in them. 



The engine can thus be made to run either forward or backward, by merely 

 pulling the hand lever w" forward or back ; and the handle is placed close to the 

 engine man, who stands behind the fire-box, so as to be readily moved ; it is fixed 

 so as to drop into the notches, and requires pulling out of them to shift its position, 

 in order to prevent its jolting loose. The suspending rods, o" d", that support the 

 ends of the eccentric rods, have to be moved with the eccentric rods in working, 

 causing some friction to the engine ; those rods that are in gear have to be held close 

 up to the pins on the levers of the weigh-bars, that they may not get out of the 

 notches in the eccentric rods ; and their motion does not exactly correspond with 

 that of the pins in the levers of the weigh-bars, from the suspending rods 

 taking hold below the notches of the eccentric rods, and moving in an arc of a rather 

 larger circle, causing a little additional friction from the sliding of the pins in the 

 notches, though the amount of it is very small. To obviate this, the eccentric rods 

 are placed in some engines above the pins in the levers of the weigh-bars, with the 

 forks and notches inverted, so as to drop down upon the pins and rest upon them 

 when in gear ; allowing the suspending rods to have a loose hold of them, as they 

 do not require support. This plan is liable to the objection, that if the eccentric 

 rods should accidentally get loose by the pins jolting out, they would all fall into 

 gear and cause the breaking of the machinery, as they move in opposite directions ; 

 but with the other arrangement the eccentric rods would in this case merely fall 

 upon a rod that is fixed under them across the engine. 



This plan of reversing has been but lately introduced, having been first used 

 by Messrs. Stephenson, and since adopted with different modifications by other 

 makers. The plan in many locomotives is, to have the four eccentric rods 

 suspended above the levers of the weigh-bars in a similar manner to the last, but 

 with notches only in their under side, so that they cannot take hold of the lever 

 pins until they have moved along, and the notches coincide with the pins ; the 



